This could be in an obsessive fashion, or hardcore girl fan style.
This could also mean someone who is completely obsessed or deluded with Katy Perry in every way and is constantly needing to get their 'KP' fix, this is known as Katy Perrying.
Person 2: "No sorry, I'm Katy Perrying all day"
Person 1: "WTF, that stupid bitch who can't sing and has big tits?"
Person 2: "STFU.... *starts crying*